The technology of the present disclosure relates to an image forming apparatus including an optical scanning device that forms a latent image on a surface to be scanned by exposure scanning, such as a copy machine, a printer, a facsimile, and a multifunctional peripheral thereof.
Conventionally, in an optical scanning device used in an image forming apparatus, the surface (the surface to be scanned) of an image carrying member is exposed and scanned and a latent image is formed on the image carrying member. In order to expose and scan beam light onto the image carrying member, when the beam light is deflected, since a rotating polygon mirror such as a polygon mirror rotates at a high speed, both a rotating shaft of a motor that rotationally drives the rotating polygon mirror and a bearing part thereof generate heat. When the heat generated in the motor rotating shaft and the bearing part is filled in a housing of the optical scanning device and the housing becomes high temperature, since the housing and an optical member such as a lens or a mirror accommodated in the housing may be thermally deformed, it is not possible to form a good latent image on the surface of the image carrying member due to the thermal deformation of the housing and an optical member.
In this regard, there has been known various technologies for suppressing an increase in the temperature of the optical scanning device due to the heat generated in the motor rotating shaft and the bearing part. As one example of the technologies, there has been proposed a configuration in which a mounting part of a polygon motor of the housing for accommodating the polygon motor is made of a member having high thermal conductivity such as aluminum material, a duct for allowing air from a fan to pass therethrough is disposed at a position just below the polygon motor, and the air is blown into the mounting part of the polygon motor, so that a polygon motor bearing part is cooled.